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Replacement Tow Doctor Tester

Replacement Tow Doctor Tester

Item # 4010509028
Our Price: $275.56
You Save: $362.13
Electrical Tools
Shipping Weight: 1.6 lbs
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Replacement Tow Doctor Tester Tow Function Tester 4010509028
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  • Reviews (7)
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  • Videos (1)
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Hopkins Electrical Tools - 4010509028

  • Testers
  • Tow Function Tester
  • Hopkins

  • Replacement tester for Hopkins Tow Doctor Trailer End Test Unit (HM50928)
  • Allows one person to check that trailer wiring and functions are working correctly
  • Tests all trailer functions: right turn, left turn, brake, tail, backup lights; electric brakes and auxiliary power
  • Trailer lights illuminate and LED bulbs light on the tester to show function operation
  • Adapts to 4-Flat, 6-Pole Round, or 7-Way RV Blade
  • Includes battery terminal clips
  • Amperage meter shows actual amp draw
  • For use with any 12-Volt battery
  • For electric brakes, magnets are activated to determine correct operation

4010509028 Hopkins Replacement Tow Doctor Trailer End Tester

4010509028 Replacement Tow Doctor Tester

California residents: click here

Video of Replacement Tow Doctor Tester

Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.

Video Transcript for Review of Hopkins Electrical Tools - Replacement Tow Doctor Tester - 4010509028

Hi there, I'm Michael with Today, we're gonna take a quick look at this Hopkins replacement tow doctor tester. This is going to replace the tester for your Hopkins tow doctor trailer end test unit. This is a direct replacement from Hopkins, so you can trust that this is going to be exactly what you need if your original tester has become damaged or for whatever reason, is no longer functioning, now this is going to have the same functionality as the original. And so, it's going to allow a single person to check that the trailer wiring and functions are working correctly. This will test all of the trailer functions, the right turn, left turn, brake, tail, backup lights, electric brakes, and auxiliary power.

The trailer lights will eliminate, and the LED bulbs will light on the tester to show the functional operation. Now, this will adapt to your six pole round, your seven-way RV blade, and your four flat trailer connectors. It includes the battery terminals. So, just like the original, it's gonna do a great job of allowing you to check to make sure that everything is working correctly. So if you are needing to replace that original tow doctor tester, this is gonna be exactly what you need.

That completes our look for today. Again, I'm Michael with, thanks for watching..

Customer Reviews

Replacement Tow Doctor Tester - 4010509028

Average Customer Rating:  4.4 out of 5 stars   (7 Customer Reviews)


Great product




Great product and as always excellent service from etrailer.


Etrailer Expert

Brooke M.


It looks like your experience with the product or with shopping at etrailer could have gone better. If you would like to add any comments to your review, I would be happy to assist you.





See what our Experts say about this Hopkins Electrical Tools

  • Trailer Wiring Circuit Tester Comparison
    Both the Tekonsha Trailer Wiring Circuit Tester # 8010 and the Hopkins Tow Doctor Trailer End Test Unit # HM50928 are for testing the wiring of your trailer. Both will work with incandescent and LED lights. However, the Hopkins will not display amperage for LED lights. They both connect the same by plugging your trailer's wiring harness into the unit. The Hopkins includes connectors for a 7-blade, a 4-pole, and 6-pole round. The Tekonsha has the 7-blade standard. If you need a different...
    view full answer...
  • Electric Trailer Brake Light Does Not Light Up When Testing with a Hopkins Tow Doctor Tester
    The replacement unit, # 4010509028 is a replacement for Tow Doctor part # HM50928. It looks like the Tow Doctor version you ordered is # HM50918. The difference is the HM50928 has more features. To test the brake controller output someone will need to sit in the truck and apply the manual override so that it is sending power back to the trailer connector. Otherwise, what will happen is what you are seeing, a slight flicker of light. That is the brake controller checking to see if a trailer...
    view full answer...

Do you have a question about this Electrical Tool?

Info for this part was:

Employee Michael H
Expert Research:
Michael H
Employee Alexander C
Updated by:
Alexander C
Employee Michael B
Installed by:
Michael B

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